Rareform
Rareform describes something that is seldom seen or found; something unusual or uncommon in its specific context. It implies a degree of uniqueness, not necessarily in inherent quality but in the infrequency of its occurrence.
The term is typically used to emphasize the scarcity or limited availability of the described subject. It can be applied to physical objects, abstract concepts, events, or even behaviors. While often used synonymously with "rare," "rareform" often carries a nuance of being specifically in a rare form or manifestation compared to other more common versions.
The word can also subtly imply a high value, whether that value is monetary, aesthetic, or symbolic, due to its scarcity. However, the primary emphasis remains on the uncommon nature of the subject.